1,3-Cyclohexanedione → 6-Chloro-4-oxo-1,2,3,4-tetrahydrocarbazole

HRID 966067Notes

Reaction equation

HRID 966067 reaction equation
Cl.[Cl:2][C:3]1[CH:8]=[CH:7][C:6]([NH:9]N)=[CH:5][CH:4]=1.[C:11]1(=O)[CH2:16][CH2:15][CH2:14][C:13](=[O:17])[CH2:12]1.ClC1C=CC(NN=C2CCCC(=O)C2)=CC=1>O.FC(F)(F)C(O)=O>[Cl:2][C:3]1[CH:8]=[C:7]2[C:6](=[CH:5][CH:4]=1)[NH:9][C:11]1[CH2:16][CH2:15][CH2:14][C:13](=[O:17])[C:12]2=1

Participants

6

Reactant 3

HCID 104341,3-CyclohexanedioneHCID 71600Hydrazine, (4-chlorophenyl)-, hydrochloride (1:1)HCID 5224489HCID 5224489, compound

Product 1

HCID 3357036-Chloro-4-oxo-1,2,3,4-tetrahydrocarbazoleYield 42%

Reagents, catalysts & solvents 2

HCID 962WaterSolvent2×HCID 6422Trifluoroacetic acidSolvent

Conditions

Temperature
80 °C

Procedure

A suspension of p-chlorophenylhydrazine hydrochloride (8.06 g, 45 mmol) in water is added over a 10 min. period to a solution of 1,3-cyclohexanedione (5.05 g, 45 mmol) in water, stirred for 16 h and filtered. The filtercake is washed with water and air-dried. The thus-obtained cyclohexane-1,3-dione mono-(4-chlorophenyl)-hydrazone (45 mmol th.) is dissolved in trifluoroacetic acid (TFA) (30 mL), heated at 80° C. for 16 h, cooled to room temperature, poured into ice-water and filtered. The filtercake is air-dried and recrystallized from ethanol/water to afford the title product as a tan solid, 4.2 g (42% yield) identified by NMR and mass spectral analyses.

Workup

  1. filtrationfiltered
  2. washThe filtercake is washed with water
  3. customair-dried
  4. temperaturecooled to room temperature
  5. filtrationfiltered
  6. customThe filtercake is air-dried
  7. customrecrystallized from ethanol/water

Sources & evidence

ORD record
ord-3b3fd6f462c6481e8d7f625da38223a7
Source dataset
uspto-grants-2005_10
Patent number
US06951881B2

Reaction notes

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